A TO type laser device that can perform long-distance transmission due to a reduced line breadth of laser light. A semiconductor laser device which comprises a laser diode chip (100) that emits laser light; a wavelength-selective filter; a collimating lens (200) disposed in a light path between the laser diode chip (100) and the wavelength-selective filter and to collimate light emitted from the laser diode chip (100); a 45°-partial reflective mirror (300) disposed in a light path between the laser diode chip (100) and the wavelength-selective filter for changing laser light traveling parallel to the bottom of a package into laser light traveling perpendicularly to the bottom of the package; and an optical wavelength supervisory photodiode (500) disposed in a light path along which laser light reflecting from the wavelength-selective filter, after being emitted from the laser diode chip (100), passes through the 45°-partial reflective mirror (300).
Legal claims defining the scope of protection, as filed with the USPTO.
1. A semiconductor laser device comprising: a laser diode chip ( 100 ) that emits laser light; a wavelength-selective filter; a collimating lens ( 200 ) that is disposed in a light path between the laser diode chip ( 100 ) and the wavelength-selective filter and collimates light emitted from the laser diode chip ( 100 ); a 45°-partial reflective mirror ( 300 ) that is disposed in a light path between the laser diode chip ( 100 ) and the wavelength-selective filter and changes laser light traveling parallel to a bottom of a package into laser light traveling perpendicularly to the bottom of the package; an optical wavelength supervisory photodiode ( 500 ) that is disposed in a light path along which laser light reflecting from the wavelength-selective filter after being emitted from the laser diode chip ( 100 ) passes through the 45°-partial reflective mirror ( 300 ); wherein an optical intensity supervisory photodiode ( 600 ) is disposed in the light path along which laser light emitted form the laser diode chip ( 100 ) passes through the 45°-partial reflective mirror ( 300 ); and wherein an oscillating wavelength of a laser is stabilized by adjusting temperature of a thermoelectric element ( 900 ) such that a value obtained by dividing a current flowing to the optical wavelength supervisory photodiode ( 500 ) by a current flowing to the optical intensity supervisory photodiodes ( 600 , 700 ) is the minimum.
2. The laser device of claim 1 , wherein the laser diode chip ( 100 ) and the wavelength-selective filter are disposed on one thermoelectric element ( 900 ).
3. The laser device of claim 2 , wherein the temperature of the thermoelectric element ( 900 ) is measured by a thermistor ( 950 ) attached thereon, and the thermistor ( 950 ) is electrically connected with an electrode pin ( 1010 ) through a thermistor connection sub-mount ( 980 ) attached on the thermoelectric element ( 900 ) separately from the thermistor ( 950 ).
4. The laser device of claim 3 , wherein the thermistor ( 950 ) is coated with a nonconductive polymer.
5. The laser device of claim 1 , wherein the wavelength-selective filter is an FP type etalon filter ( 400 ).
7. The laser device of claim 6 , wherein the frequency separation of the desired transmissive wavelength is any one of 25, 50, 100, and 200.
8. The laser device of claim 1 , wherein the wavelength-selective filter is manufactured by stacking dielectric thin films having high and low refractive indexes.
9. The laser device of claim 1 , wherein an optical intensity supervisory photodiode ( 700 ) is disposed in a light path along which laser light emitted from a rear side of the laser diode chip ( 100 ) travels.
10. The laser device of claim 1 , wherein a line breadth of a transmissive wavelength band of the wavelength-selective filter is 0.5 nm or less.
11. The laser device of claim 1 , wherein the 45°-partial reflective mirror ( 300 ) is inserted and fixed in a through-hole ( 351 ) of a stand ( 350 ) that is a hexahedral silicon substrate having a through-hole ( 351 ) at an angle of 45° with respect to any one side by dry etching, and is installed at an angle of 45° with respect to a floor.
12. The laser device of claim 1 , wherein a photodiode sub-mounts ( 610 , 710 ) is made of silicon, which is a base material, and has a metallic pattern continuous on a first side ( 101 ) and a second side ( 111 ) of the silicon.
13. The laser device of claim 1 , wherein the 45°-partial reflective mirror ( 300 ) is 0.1 mm to 0.25 mm thick.
14. The laser device of claim 1 , wherein the optical wavelength supervisory photodiode ( 500 ) is attached on the thermoelectric element ( 900 ).
15. The laser device of claim 1 , wherein the wavelength-selective filter is manufactured by stacking dielectric thin films having high and low refractive indexes on either a glass or a quartz substrate.
16. The laser device of claim 1 , wherein the wavelength-selective filter is manufactured by stacking dielectric thin films having high and low refractive indexes on a semiconductor substrate including any one of silicon, InP, and GaAs.
17. The laser device of claim 16 , wherein a thin film heater is further attached to the wavelength-selective filter.
18. A semiconductor laser device comprising: a laser diode chip ( 100 ) that emits laser light; a wavelength-selective filter; a collimating lens ( 200 ) that is disposed in a light path between the laser diode chip ( 100 ) and the wavelength-selective filter and collimates light emitted from the laser diode chin ( 100 ); a 45°-partial reflective mirror ( 300 ) that is disposed in a light path between the laser diode chip ( 100 ) and the wavelength-selective filter and changes laser light traveling parallel to the bottom of a package into laser light traveling perpendicularly to the bottom of the package; an optical wavelength supervisory photodiode ( 500 ) that is disposed in a light path along which laser light reflecting from the wavelength-selective filter after being emitted from the laser diode chip ( 100 ) asses through the 45′-partial reflective mirror ( 300 ); wherein an optical intensity supervisory photodiode ( 600 ) is disposed in the light path along which laser light emitted from the laser diode chip ( 100 ) passes through the 45°-partial reflective mirror ( 300 ); and wherein the laser diode chip ( 100 ) and the wavelength-selective filter are disposed on one thermoelectric element ( 900 ) and the temperature of the thermoelectric element ( 900 ) is adjusted such that ratios of a photocurrent flowing to the optical wavelength supervisory photodiode ( 500 ) and a photocurrent flowing to the optical intensity supervisory photodiode ( 600 , 700 ) is constant.
19. A semiconductor laser device comprising: a laser diode chip ( 100 ) that emits laser light; a wavelength-selective filter; a collimating lens ( 200 ) that is disposed in a light path between the laser diode chip ( 100 ) and the wavelength-selective filter and collimates light emitted from the laser diode chip ( 100 ); a 45°-partial reflective mirror ( 300 ) that is disposed in a light path between the laser diode chip ( 100 ) and the wavelength-selective filter and changes laser light traveling parallel to the bottom of a package into laser light traveling perpendicularly to the bottom of the package; an optical wavelength supervisory photodiode ( 500 ) that is disposed in a light path along which laser light reflecting from the wavelength-selective filter after being emitted from the laser diode chip ( 100 ) passes through the 45°-partial reflective mirror ( 300 ); wherein an optical intensity supervisory photodiode ( 600 ) is disposed in the light path along which laser light emitted from the laser diode chip ( 100 ) passes through the 45°-partial reflective mirror ( 300 ); and wherein the wavelength-selective filter is manufactured by stacking dielectric thin films having high and low refractive indexes on a semiconductor substrate including any one of silicon, InP, and GaAs and the temperature of the wavelength-selective filter is adjusted such that ratios of a photocurrent flowing to the optical wavelength supervisory photodiode ( 500 ) and a photocurrent flowing to the optical intensity supervisory photodiodes ( 600 , 700 ) is constant.
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May 12, 2014
December 6, 2016
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